Xerophyte

Central Spines

Usually 1 rather larger.

Flowers

At apex, large, lemon-yellow 7-12 cm broad, inner perianth segments broadly oblong, with a broad, more or less serrated apex, tube short woolly, scale on ovary, dark and very narrow.

Ribs

It has 5 to 10 (generally 8) straight or frequently spiralling, rather prominent, strongly compressed, more or less sinuate and crenate .

Stem

The stem is solitary, globose when young, shortly columnar with age, 30 to 120 cm (or more) high, 15-30 cm across, greyish-green to dark-green with dense white flakes in covering more or less uniformly the epidermis.

Radial Spines

5-11 stout, 2-4 cm long usually straight, subulated or ± laterally compressed, amber yellow, later brown and finally grey.

Areoles

1 to 5 cm apart, at first yellowish-white felted, later grabrescent.